The smartypants who design the brains inside each of Apple’s iOS devices--the iPhone, iPad, iPhone touch, and Apple TV--have announced a new processor scheme with far-reaching implications not only for Apple’s überpopular consumer lineup, but for MacBooks, as well. And those designers aren’t Cupertinians.
I know, I know--Apple crows that they design the processors in those devices. They’re not lying, but they are stretching the truth a wee bit. Each iDevice’s cerebrum was designed by ARM Holdings, a company in Cambridge, England. Apple licensed ARM’s designs, along with graphics-core designs from another British firm, Imagination Technologies, to build its A4 and A5 processors.
Warning: I’m about to overuse the letter “A” for a bit. Apple’s A4 uses a compute core called the ARM Cortex-A8, which first appeared in the original iPad, then migrated to the iPhone 4, iPod touch, and Apple TV. Apple’s A5 uses the dual-core ARM Cortex-A9 MPCore, which debuted in the iPad 2 and has since spread to the iPhone 4S.
ARM compute cores dominate the mobile market, powering nearly every smartphone on the planet, as well as such iPad competitors as the Motorola Xoom, BlackBerry PlayBook, and Samsung Galaxy Tab. And now ARM has introduced a new low-power core, the Cortex-A7 MPCore, and will marry it with its soon-to appear high-end core, the A15, into a single design that it has dubbed big.LITTLE.
Trust me, this is important. The A15 is a muscular design, able to take care of such demanding tasks as video encoding and decoding, complex gaming, and multiprocessing, all without breaking a sweat. Unfortunately, though, its oomph-producing chippery requires a lot of transistors. The more transistors, the more juice a chip needs, and the more juice it needs, the shorter its battery life.
The fruits of ARM’s recent efforts won’t be seen in the immediate future, but hopefully before we get close to the A14.
Enter the tiny new A7 core. This li’l baby requires a tiny fraction of the A15’s juice, but it’s more than capable of handling such mundane tasks as email, updating your Facebook page, making phone calls, and Tweeting your dinner plans to your 13 followers.
With big.LITTLE, ARM has put both the A7 and the A15 onto the same chip, and has tweaked that design so that a device’s operating system doesn’t need to know which core is doing what when. The big.
LITTLE system will look at a task that iOS sends it, and if the power-hungry A15 cores are needed--both the A7 and A15 can have up to four cores, by the way--they’ll be fired up. If not, the task will be handed to the A7 cores, and humongous amounts of battery juice will be saved. It’s the Prius of processors.
This mash-up won’t find its way into the market until 2013, so don’t look for it in Apple’s A6 or A7--A14, anyone? And don’t expect it to appear only in iPhones and iPads. Apple has been widely rumored to be toying with a MacBook Air follow-on that won’t run Mac OS X, but iOS. A big.LITTLE processor would be a natural for such a device.
Remember, iOS is based on Mac OS X. I’d be willing to bet that somewhere at One Infinite Loop, some top-flight Apple techies are running a version of Mac OS X on the ARM architecture at this very minute. After all, every version of Mac OS X was ported to the Intel architecture well before Steve Jobs announced the move from PowerPC to Intel in 2005.
If only we could get ARM to change the dumb name of its new scheme: big.LITTLE. Honestly.
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Since the late 1980s, Rik Myslewski has paid his rent by keeping an eye on Apple. He was editor-in-chief of MacAddict from 2001 until its transformation into Mac|Life in early 2007, and is now a member of the snarkily sophisticated team at London’s The Register, which is “biting the hand that feeds IT” daily at www.theregister.co.uk.
